It’s official: The House of Representatives has impeached president Donald Trump. Now, Americans are demanding a real trial: More than 70 percent of Americans—including almost two-thirds of Republicans—want top administration officials such as former national security adviser John Bolton and acting White House Chief of Staff Mick Mulvaney to testify.

Instead, Senate Majority Leader Mitch McConnell (R-KY) is covering for the president. After announcing that he would be coordinating his position with the president, McConnell shot down requests to have Bolton, Mulvaney, or any of the other witnesses whose testimony the White House has blocked appear before the Senate. In doing so, McConnell has made himself complicit in Trump’s unprecedented obstruction of Congress, which began months before news of the Ukraine scandal broke. As the articles of impeachment note, Trump’s efforts to block the Ukraine investigation do not exist in a vacuum; rather, they are “consistent with President Trump’s previous efforts to undermine United States Government investigations into foreign interference in United States elections.”

The Trump administration has been obstructing Congress since the moment the Mueller report was completed.

• In a Senate hearing just after the report was released, U.S. Attorney General William Barr refused to commit to releasing the full report, even to Congress. He also dismissed reports that Robert Mueller’s team had rejected his “nothing to see here” interpretation of their investigation but refused to let Congress see notes he claimed supported his account.
• The next day, Barr was a no-show at his scheduled testimony before the House, making him the first of more than a dozen witnesses in the Russia and Ukraine investigations who have bucked congressional requests to testify.
• Seven months later, even as reports and documents obtained via the Freedom of Information Act suggest that the president may have lied to cover up his and his campaign’s crimes, most of Congress still has not seen the full, unredacted report.

Attorney General Barr’s stonewalling was the opening shot in a now monthslong effort to prevent Congress from doing its duty:

• In March, the House Judiciary Committee requested documents and testimony from 81 individuals and organizations as they planned to continue the Russia investigation. Since then, only one—Corey Lewandowski—has publicly testified before Congress.
• Days after the Mueller report came out, Congress subpoenaed Don McGahn, one of the key witnesses in Mueller’s investigation. The White House has tied up that subpoena in the courts for almost eight months, with no end in sight.
• Meanwhile, the White House has chased a lawsuit to prevent Congress from seeing President Trump’s tax returns all the way to the Supreme Court.

The obstruction of Congress is just one part of Trump’s broader obstruction of justice:

• The Mueller report devoted almost 200 pages to chronicling 10 ways Trump himself appears to have tried to obstruct justice, ranging from his efforts to fire those investigating him—Mueller included—to dangling pardons and tampering with witnesses against him.
  • After the Mueller report came out, more than 1,000 former federal prosecutors signed an open letter arguing that if Trump were not president, he would likely have been indicted for obstruction of justice.
• The report also strongly suggests that members of Trump’s team may have deleted records of incriminating conversations or used encrypted messaging services to obstruct the investigation. For example, the account of Erik Prince and Steve Bannon’s conversations during the transition contains multiple references to conspicuous gaps in the record of messages between the two. Both Prince and Bannon deny that they deleted or covered up any messages to hide them from investigators.
• Revelations about President Trump and his team’s efforts to obstruct the Mueller investigation have continued: In recent sentencing hearings for deputy Trump campaign chairman Rick Gates, prosecutors said that he received “assurances of monetary assistance” if he refused to cooperate with prosecutors, while evidence in the trial of Roger Stone strongly suggests that President Trump lied in his written answers to Mueller.

The Russia and Ukraine investigations are not the only ones that President Trump is trying to obstruct. His administration is engaged in an unprecedented effort to prevent Congress from fulfilling its constitutionally mandated duty to oversee the executive branch. And while Trump’s efforts to solicit foreign interference undermine free and fair elections, his obstruction is impeachable as well, as it goes against a fundamental tenet of American democracy: Nobody, not even the president, is above the law.